Fig. 4. The azimuthally averaged centroid (top panel) and the thickness (HWHM) of the massive star formation layer (bottom panel) are shown for the northern () Galaxy (left); the southern () Galaxy (center); and the complete Galaxy (right)
![[FIGURE]](img98.gif)
![[FORMULA]](img90.gif)
(top panel) and the thickness (HWHM) ![[FORMULA]](img92.gif)
of the massive star formation layer (bottom panel) are shown for the northern (![[FORMULA]](img94.gif)
) Galaxy (left); the southern (![[FORMULA]](img96.gif)
) Galaxy (center); and the complete Galaxy (right)